Color Doppler sonography has become an integral part of modern hepatic sonography. Color Doppler can enhance the conspicuity of focal lesions and bile ducts in jaundiced patients by illuminating normal vessels with flow. Spectral and color Doppler may prove useful in limiting the sonographic differential diagnosis of focal liver lesions. Color flow sonography effectively evaluates pseudoaneurysms, A-V fistulae, collaterals, and flow reversal in portal hypertension, venous clot and tumor invasion, Budd-Chiari syndrome, hereditary hemorrhagic telangiectasis, and many other hepatic vascular lesions. We have found it invaluable in evaluating cirrhotic and liver transplant patients.